<?php // $Id: view_table_php.class.php,v 1.14.2.1 2007/11/01 23:21:42 stronk7 Exp $

///////////////////////////////////////////////////////////////////////////
//																	   //
// NOTICE OF COPYRIGHT												   //
//																	   //
// Moodle - Modular Object-Oriented Dynamic Learning Environment		 //
//		  http://moodle.com											//
//																	   //
// Copyright (C) 1999 onwards Martin Dougiamas	 http://dougiamas.com  //
//		   (C) 2001-3001 Eloy Lafuente (stronk7) http://contiento.com  //
//																	   //
// This program is free software; you can redistribute it and/or modify  //
// it under the terms of the GNU General Public License as published by  //
// the Free Software Foundation; either version 2 of the License, or	 //
// (at your option) any later version.								   //
//																	   //
// This program is distributed in the hope that it will be useful,	   //
// but WITHOUT ANY WARRANTY; without even the implied warranty of		//
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the		 //
// GNU General Public License for more details:						  //
//																	   //
//		  http://www.gnu.org/copyleft/gpl.html						 //
//																	   //
///////////////////////////////////////////////////////////////////////////

/// This class will show the PHP needed to perform the desired action
/// with the specified fields/keys/indexes.

class view_table_php extends XMLDBAction {

	/**
	 * Init method, every subclass will have its own
	 */
	function init() {
		parent::init();

	/// Set own custom attributes

	/// Get needed strings
		$this->loadStrings(array(
			'selectaction' => 'xmldb',
			'selectfieldkeyindex' => 'xmldb',
			'view' => 'xmldb',
			'table' => 'xmldb',
			'selectonecommand' => 'xmldb',
			'selectonefieldkeyindex' => 'xmldb',
			'mustselectonefield' => 'xmldb',
			'mustselectonekey' => 'xmldb',
			'mustselectoneindex' => 'xmldb',
			'back' => 'xmldb'
		));
	}

	/**
	 * Invoke method, every class will have its own
	 * returns true/false on completion, setting both
	 * errormsg and output as necessary
	 */
	function invoke() {
		parent::invoke();

		$result = true;

	/// Set own core attributes
		$this->does_generate = ACTION_GENERATE_HTML;

	/// These are always here
		global $CFG, $XMLDB;

	/// Do the job, setting result as needed
	/// Get the dir containing the file
		$dirpath = required_param('dir', PARAM_PATH);
		$dirpath = $CFG->dirroot . stripslashes_safe($dirpath);

	/// Get the correct dirs
		if (!empty($XMLDB->dbdirs)) {
			$dbdir =& $XMLDB->dbdirs[$dirpath];
		} else {
			return false;
		}
		if (!empty($XMLDB->editeddirs)) {
			$editeddir =& $XMLDB->editeddirs[$dirpath];
			$structure =& $editeddir->xml_file->getStructure();
		}
	/// ADD YOUR CODE HERE

		$tableparam = required_param('table', PARAM_PATH);

		$table =& $structure->getTable($tableparam);
		$fields = $table->getFields();
		$field = reset($fields);
		$defaultfieldkeyindex = null;
		if ($field) {
			$defaultfieldkeyindex = 'f#' . $field->getName();
		}
		$keys = $table->getKeys();
		$indexes = $table->getIndexes();

	/// Get parameters
		$commandparam = optional_param('command', 'add_field', PARAM_PATH);
		$origfieldkeyindexparam = optional_param('fieldkeyindex', $defaultfieldkeyindex, PARAM_PATH);
		$fieldkeyindexparam = preg_replace('/[fki]#/i', '', $origfieldkeyindexparam); ///Strip the initials
		$fieldkeyindexinitial = substr($origfieldkeyindexparam, 0, 1); //To know what we have selected

	/// The back to edit xml button
		$b = ' <p class="centerpara buttons">';
		$b .= '<a href="index.php?action=edit_table&amp;dir=' . urlencode(str_replace($CFG->dirroot, '', $dirpath)) . '&amp;table=' . $tableparam . '">[' . $this->str['back'] . ']</a>';
		$b .= '</p>';
		$o = $b;

	/// The table currently being edited
		$o .= '<h3 class="main">' . $this->str['table'] . ': ' . s($tableparam) . '</h3>';

	/// To indent the menu selections
		$optionspacer = '&nbsp;&nbsp;&nbsp;';

	/// Calculate the popup of commands
		$commands = array('Fields',
						 $optionspacer . 'add_field',
						 $optionspacer . 'drop_field',
						 $optionspacer . 'rename_field',
						 $optionspacer . 'change_field_type',
						 $optionspacer . 'change_field_precision',
						 $optionspacer . 'change_field_unsigned',
						 $optionspacer . 'change_field_notnull',
						 $optionspacer . 'change_field_enum',
						 $optionspacer . 'change_field_default',
						 'Keys',
						 $optionspacer . 'add_key',
						 $optionspacer . 'drop_key',
						 $optionspacer . 'rename_key',
						 'Indexes',
						 $optionspacer . 'add_index',
						 $optionspacer . 'drop_index',
						 $optionspacer . 'rename_index');
		foreach ($commands as $command) {
			$popcommands[str_replace($optionspacer, '', $command)] = str_replace('_', ' ', $command);
		}
	/// Calculate the popup of fields/keys/indexes
		if ($fields) {
			$popfields['fieldshead'] = 'Fields';
			foreach ($fields as $field) {
				$popfields['f#' . $field->getName()] = $optionspacer . $field->getName();
			}
		}
		if ($keys) {
			$popfields['keyshead'] = 'Keys';
			foreach ($keys as $key) {
				$popfields['k#' . $key->getName()] = $optionspacer . $key->getName();
			}
		}
		if ($indexes) {
			$popfields['indexeshead'] = 'Indexes';
			foreach ($indexes as $index) {
				$popfields['i#' . $index->getName()] = $optionspacer . $index->getName();
			}
		}

	/// Now build the form
		$o.= '<form id="form" action="index.php" method="post">';
		$o.= '<div>';
		$o.= '	<input type="hidden" name ="dir" value="' . str_replace($CFG->dirroot, '', $dirpath) . '" />';
		$o.= '	<input type="hidden" name ="table" value="' . s($tableparam) . '" />';
		$o.= '	<input type="hidden" name ="action" value="view_table_php" />';
		$o.= '	<table id="formelements" class="boxaligncenter" cellpadding="5">';
		$o.= '	  <tr><td><label for="action" accesskey="c">' . $this->str['selectaction'] .' </label>' . choose_from_menu($popcommands, 'command', $commandparam, '', '', 0, true) . '&nbsp;<label for="fieldkeyindex" accesskey="f">' . $this->str['selectfieldkeyindex'] . ' </label>' .choose_from_menu($popfields, 'fieldkeyindex', $origfieldkeyindexparam, '', '', 0, true) . '</td></tr>';
		$o.= '	  <tr><td colspan="2" align="center"><input type="submit" value="' .$this->str['view'] . '" /></td></tr>';
		$o.= '	</table>';
		$o.= '</div></form>';

		$o.= '	<table id="phpcode" class="boxaligncenter" cellpadding="5">';
		$o.= '	  <tr><td><textarea cols="80" rows="32">';
	/// Check we have selected some field/key/index from the popup
		if ($fieldkeyindexparam == 'fieldshead' || $fieldkeyindexparam == 'keyshead' || $fieldkeyindexparam == 'indexeshead') {
			$o.= s($this->str['selectonefieldkeyindex']);
	/// Check we have selected some command from the popup
		} else if ($commandparam == 'Fields' || $commandparam == 'Keys' || $commandparam == 'Indexes') {
			$o.= s($this->str['selectonecommand']);
		} else {
		/// Based on current params, call the needed function
			switch ($commandparam) {
				case 'add_field':
					if ($fieldkeyindexinitial == 'f') { //Only if we have got one field
						$o.= s($this->add_field_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectonefield'];
					}
					break;
				case 'drop_field':
					if ($fieldkeyindexinitial == 'f') { //Only if we have got one field
						$o.= s($this->drop_field_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectonefield'];
					}
					break;
				case 'rename_field':
					if ($fieldkeyindexinitial == 'f') { //Only if we have got one field
						$o.= s($this->rename_field_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectonefield'];
					}
					break;
				case 'change_field_type':
					if ($fieldkeyindexinitial == 'f') { //Only if we have got one field
						$o.= s($this->change_field_type_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectonefield'];
					}
					break;
				case 'change_field_precision':
					if ($fieldkeyindexinitial == 'f') { //Only if we have got one field
						$o.= s($this->change_field_precision_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectonefield'];
					}
					break;
				case 'change_field_unsigned':
					if ($fieldkeyindexinitial == 'f') { //Only if we have got one field
						$o.= s($this->change_field_unsigned_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectonefield'];
					}
					break;
				case 'change_field_notnull':
					if ($fieldkeyindexinitial == 'f') { //Only if we have got one field
						$o.= s($this->change_field_notnull_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectonefield'];
					}
					break;
				case 'change_field_enum':
					if ($fieldkeyindexinitial == 'f') { //Only if we have got one field
						$o.= s($this->change_field_enum_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectonefield'];
					}
					break;
				case 'change_field_default':
					if ($fieldkeyindexinitial == 'f') { //Only if we have got one field
						$o.= s($this->change_field_default_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectonefield'];
					}
					break;
				case 'add_key':
					if ($fieldkeyindexinitial == 'k') { //Only if we have got one key
						$o.= s($this->add_key_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectonekey'];
					}
					break;
				case 'drop_key':
					if ($fieldkeyindexinitial == 'k') { //Only if we have got one key
						$o.= s($this->drop_key_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectonekey'];
					}
					break;
				case 'rename_key':
					if ($fieldkeyindexinitial == 'k') { //Only if we have got one key
						$o.= s($this->rename_key_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectonekey'];
					}
					break;
				case 'add_index':
					if ($fieldkeyindexinitial == 'i') { //Only if we have got one index
						$o.= s($this->add_index_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectoneindex'];
					}
					break;
				case 'drop_index':
					if ($fieldkeyindexinitial == 'i') { //Only if we have got one index
						$o.= s($this->drop_index_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectoneindex'];
					}
					break;
				case 'rename_index':
					if ($fieldkeyindexinitial == 'i') { //Only if we have got one index
						$o.= s($this->rename_index_php($structure, $tableparam, $fieldkeyindexparam));
					} else {
						$o.= $this->str['mustselectoneindex'];
					}
					break;
			}
		}
		$o.= '</textarea></td></tr>';
		$o.= '	</table>';

		$this->output = $o;

	/// Launch postaction if exists (leave this here!)
		if ($this->getPostAction() && $result) {
			return $this->launch($this->getPostAction());
		}

	/// Return ok if arrived here
		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * create one field using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string field field name to be created
	 * @return string PHP code to be used to create the field
	 */
	function add_field_php($structure, $table, $field) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$field = $table->getField($field)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Define field ' . $field->getName() . ' to be added to ' . $table->getName() . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field = new XMLDBField(' . "'" . $field->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field->setAttributes(' . $field->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch add field ' . $field->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && add_field($table, $field);' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * drop one field using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string field field name to be dropped
	 * @return string PHP code to be used to drop the field
	 */
	function drop_field_php($structure, $table, $field) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$field = $table->getField($field)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Define field ' . $field->getName() . ' to be dropped from ' . $table->getName() . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field = new XMLDBField(' . "'" . $field->getName() . "'" . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch drop field ' . $field->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && drop_field($table, $field);' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * rename one field using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string field field name to be renamed
	 * @return string PHP code to be used to rename the field
	 */
	function rename_field_php($structure, $table, $field) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$field = $table->getField($field)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Rename field ' . $field->getName() . ' on table ' . $table->getName() . ' to NEWNAMEGOESHERE'. XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field = new XMLDBField(' . "'" . $field->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field->setAttributes(' . $field->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch rename field ' . $field->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && rename_field($table, $field, ' . "'" . 'NEWNAMEGOESHERE' . "'" . ');' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * change the type of one field using XMLDB objects and functions.
	 * Currently these conversions are supported:
	 *	 integer to char
	 *	 char to integer
	 *	 number to char
	 *	 char to number
	 *	 float to char
	 *	 char to float
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string field field name to change precision
	 */
	function change_field_type_php($structure, $table, $field) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$field = $table->getField($field)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Calculate the type tip text
		$type = $field->getXMLDBTypeName($field->getType());

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Changing type of field ' . $field->getName() . ' on table ' . $table->getName() . ' to ' . $type . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field = new XMLDBField(' . "'" . $field->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field->setAttributes(' . $field->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch change of type for field ' . $field->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && change_field_type($table, $field);' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * change the precision of one field using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string field field name to change precision
	 */
	function change_field_precision_php($structure, $table, $field) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$field = $table->getField($field)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Calculate the precision tip text
		$precision = '(' . $field->getLength();
		if ($field->getDecimals()) {
			$precision .= ', ' . $field->getDecimals();
		}
		$precision .= ')';

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Changing precision of field ' . $field->getName() . ' on table ' . $table->getName() . ' to ' . $precision . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field = new XMLDBField(' . "'" . $field->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field->setAttributes(' . $field->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch change of precision for field ' . $field->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && change_field_precision($table, $field);' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * change the unsigned/signed of one field using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string field field name to change unsigned/signed
	 */
	function change_field_unsigned_php($structure, $table, $field) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$field = $table->getField($field)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Calculate the unsigned tip text
		$unsigned = $field->getUnsigned() ? 'unsigned' : 'signed';

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Changing sign of field ' . $field->getName() . ' on table ' . $table->getName() . ' to ' . $unsigned . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field = new XMLDBField(' . "'" . $field->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field->setAttributes(' . $field->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch change of sign for field ' . $field->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && change_field_unsigned($table, $field);' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * change the nullability of one field using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string field field name to change null/not null
	 */
	function change_field_notnull_php($structure, $table, $field) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$field = $table->getField($field)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Calculate the notnull tip text
		$notnull = $field->getNotnull() ? 'not null' : 'null';

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Changing nullability of field ' . $field->getName() . ' on table ' . $table->getName() . ' to ' . $notnull . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field = new XMLDBField(' . "'" . $field->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field->setAttributes(' . $field->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch change of nullability for field ' . $field->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && change_field_notnull($table, $field);' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * change the enum values (check constraint) of one field 
	 * using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string field field name to change its enum
	 */
	function change_field_enum_php($structure, $table, $field) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$field = $table->getField($field)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Calculate the enum tip text
		$enum = $field->getEnum() ? implode(', ', $field->getEnumValues()) : 'none';

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Changing list of values (enum) of field ' . $field->getName() . ' on table ' . $table->getName() . ' to ' . $enum . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field = new XMLDBField(' . "'" . $field->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field->setAttributes(' . $field->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch change of list of values for field ' . $field->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && change_field_enum($table, $field);' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * change the default of one field using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string field field name to change null/not null
	 */
	function change_field_default_php($structure, $table, $field) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$field = $table->getField($field)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Calculate the default tip text
		$default = $field->getDefault() === null ? 'drop it' : $field->getDefault();

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Changing the default of field ' . $field->getName() . ' on table ' . $table->getName() . ' to ' . $default . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field = new XMLDBField(' . "'" . $field->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$field->setAttributes(' . $field->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch change of default for field ' . $field->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && change_field_default($table, $field);' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * create one key using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string key key name to be created
	 * @return string PHP code to be used to create the key
	 */
	function add_key_php($structure, $table, $key) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$key = $table->getKey($key)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Define key ' . $key->getName() . ' ('. $key->getXMLDBKeyName($key->getType()) . ') to be added to ' . $table->getName() . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$key = new XMLDBKey(' . "'" . $key->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$key->setAttributes(' . $key->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch add key ' . $key->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && add_key($table, $key);' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * drop one key using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string key key name to be dropped
	 * @return string PHP code to be used to drop the key
	 */
	function drop_key_php($structure, $table, $key) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$key = $table->getKey($key)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Define key ' . $key->getName() . ' ('. $key->getXMLDBKeyName($key->getType()) . ') to be dropped form ' . $table->getName() . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$key = new XMLDBKey(' . "'" . $key->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$key->setAttributes(' . $key->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch drop key ' . $key->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && drop_key($table, $key);' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * rename one key using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string key key name to be renamed
	 * @return string PHP code to be used to rename the key
	 */
	function rename_key_php($structure, $table, $key) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$key = $table->getKey($key)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Prepend warning. This function isn't usable!
		$result .= 'DON\'T USE THIS FUNCTION (IT\'S ONLY EXPERIMENTAL). SOME DBs DON\'T SUPPORT IT!' . XMLDB_LINEFEED . XMLDB_LINEFEED;

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Define key ' . $key->getName() . ' ('. $key->getXMLDBKeyName($key->getType()) . ') to be renamed to NEWNAMEGOESHERE' . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$key = new XMLDBKey(' . "'" . $key->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$key->setAttributes(' . $key->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch rename key ' . $key->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && rename_key($table, $key, ' . "'" . 'NEWNAMEGOESHERE' . "'" . ');' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * create one index using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string index index name to be created
	 * @return string PHP code to be used to create the index
	 */
	function add_index_php($structure, $table, $index) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$index = $table->getIndex($index)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Define index ' . $index->getName() . ' ('. ($index->getUnique() ? 'unique' : 'not unique') . ') to be added to ' . $table->getName() . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$index = new XMLDBIndex(' . "'" . $index->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$index->setAttributes(' . $index->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch add index ' . $index->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && add_index($table, $index);' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * drop one index using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string index index name to be dropped
	 * @return string PHP code to be used to drop the index
	 */
	function drop_index_php($structure, $table, $index) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$index = $table->getIndex($index)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Define index ' . $index->getName() . ' ('. ($index->getUnique() ? 'unique' : 'not unique') . ') to be dropped form ' . $table->getName() . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$index = new XMLDBIndex(' . "'" . $index->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$index->setAttributes(' . $index->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch drop index ' . $index->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && drop_index($table, $index);' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate all the PHP code needed to
	 * rename one index using XMLDB objects and functions
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @param string table table name
	 * @param string index index name to be renamed
	 * @return string PHP code to be used to rename the index
	 */
	function rename_index_php($structure, $table, $index) {

		$result = '';
	/// Validate if we can do it
		if (!$table = $structure->getTable($table)) {
			return false;
		}
		if (!$index = $table->getIndex($index)) {
			return false;
		}
		if ($table->getAllErrors()) {
			return false;
		}

	/// Prepend warning. This function isn't usable!
		$result .= 'DON\'T USE THIS FUNCTION (IT\'S ONLY EXPERIMENTAL). SOME DBs DON\'T SUPPORT IT!' . XMLDB_LINEFEED . XMLDB_LINEFEED;

	/// Add the standard PHP header
		$result .= XMLDB_PHP_HEADER;

	/// Add contents
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Define index ' . $index->getName() . ' ('. ($index->getUnique() ? 'unique' : 'not unique') . ') to be renamed to NEWNAMEGOESHERE' . XMLDB_LINEFEED;
		$result .= '		$table = new XMLDBTable(' . "'" . $table->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$index = new XMLDBIndex(' . "'" . $index->getName() . "'" . ');' . XMLDB_LINEFEED;
		$result .= '		$index->setAttributes(' . $index->getPHP(true) . ');' . XMLDB_LINEFEED;

	/// Launch the proper DDL
		$result .= XMLDB_LINEFEED;
		$result .= '	/// Launch rename index ' . $index->getName() . XMLDB_LINEFEED;
		$result .= '		$result = $result && rename_index($table, $index, ' . "'" . 'NEWNAMEGOESHERE' . "'" . ');' . XMLDB_LINEFEED;

	/// Add the proper upgrade_xxxx_savepoint call
		$result .= $this->upgrade_savepoint_php ($structure);

	/// Add standard PHP footer
		$result .= XMLDB_PHP_FOOTER;

		return $result;
	}

	/**
	 * This function will generate the PHP code needed to
	 * implement the upgrade_xxxx_savepoint() php calls in
	 * upgrade code generated from the editor
	 *
	 * @param XMLDBStructure structure object containing all the info
	 * @return string PHP code to be used to stabilish a savepoint
	 */
	function upgrade_savepoint_php ($structure) {

		$path = $structure->getPath();

		$result = '';

		switch ($path) {
			case 'lib/db':
				$result = XMLDB_LINEFEED .
						  '	/// Main savepoint reached' . XMLDB_LINEFEED .
						  '		upgrade_main_savepoint($result, XXXXXXXXXX);' . XMLDB_LINEFEED;
				break;
		}
		return $result;
	}

}
?>
